Background: Immune responses play significant roles in protection against leishmaniasis. Polymorphisms within the interleukin 4 receptor alpha chain (IL-4Rα) gene affect the production of cytokines, which is important for the clearance of many pathogens. The aim of the current study was to identify the relationship between visceral leishmaniasis (VL) infection and polymorphisms at positions T1432C and A1652G of IL-4Rα in an Iranian population.
Materials and methods: This cross-sectional study was performed during 2004-2012 and included three groups of participants: VL patients (Group 1, n = 124), seropositive healthy controls (Group 2, n = 101), and seronegative healthy controls (Group 3, n = 55). The IL-4Rα T1432C and A1652G polymorphisms were evaluated using a polymerase chain reaction-restriction fragment length polymorphism technique, and anti-Leishmania antibody titers were determined by using immunofluorescence technique. Alleles and genotypes were compared between groups of the study as well as Groups 1 and 2 based on the titer of antibodies. The validity of the data was analyzed using Hardy-Weinberg equilibrium and one-way analysis of variance, as well as χ (2) tests.
Results: The polymorphisms at IL-4Rα positions T1432C and A1652G were significantly associated with active VL infection. These results demonstrated that the IL-4Rα T1432C and A1652G polymorphisms were not associated with anti-Leishmania antibody production.
Conclusion: Our results indicate that these IL-4Rα polymorphisms may be risk factors for the development of VL.
Keywords: Genetic variations; interleukin-4; visceral leishmaniasis.